1. Field of the Invention
The invention relates to a suspension apparatus.
2. Description of Related Art
A suspension apparatus is installed in a vehicle to secure passenger comfort during travel and secure a road surface tracking ability of a vehicle wheel. The suspension apparatus includes an elastic body, such as a spring, provided between a vehicle body and the vehicle wheel. When the elastic body elastically deforms, a relative positional relationship between the vehicle body and the vehicle wheel varies in accordance with a condition of a road surface on which the vehicle is traveling, and as a result, shock received on the vehicle body side from the road surface can be absorbed. The suspension apparatus is further provided with a damping mechanism that damps periodic vibration accompanying the elastic deformation of the elastic body. Furthermore, a technique for varying friction generated in the damping mechanism during damping of the periodic vibration of the elastic body in accordance with a travel condition of the vehicle has been developed recently to achieve a further improvement in passenger comfort during vehicle travel.
In the suspension apparatus described above, fine control of an actuator and so on are required to vary the friction generated in the damping mechanism during damping of the periodic vibration of the elastic body, and therefore a configuration of the suspension apparatus tends to increase in complexity. Hence, demand exists for a further improvement in passenger comfort during vehicle travel using a suspension apparatus having a simple configuration.